Subject: Space-tech Digest #122 Contents: GIF space images wanted (2 msgs) UTASROC (Australian liquid rocket project) (1 msg) Should I renew my SSI membership? (9 msgs) About Space Digest (3 msgs) Status Report on Big Dumb Hybrid (1 msg) ------------------------------------------------------------ Date: Thu, 7 May 92 07:14:36 CDT From: ssi!lfa@uunet.UU.NET (Louis F. Adornato) To: uunet!cs.cmu.edu!space-tech@uunet.UU.NET Subject: GIF images wanted I'm going to be making a presentation on space exploration at the local elementary school, and I'm a little light on visual aids. Anyone know of a source of public domain space images in GIF format? BTW, if anyone's interested, I can post the outline of the presentation for critique. Lou Adornato | "Sure, the cow may have jumped over the Supercomputer Systems, Inc | moon, but she burned up on reentry" Eau Claire, WI | The secretary (and the rest of the company) uunet!ssi!lfa or lfa@ssi.com | have disavowed any knowledge of my actions. ------------------------------ Date: Thu, 7 May 1992 9:42:57 -0500 (CDT) From: JRL8574@VENUS.TAMU.EDU Subject: RE: GIF images wanted To: space-tech@cs.cmu.edu Sender: mnr@DAISY.LEARNING.CS.CMU.EDU Try looking at the FTP site, VAB02.LARC.NASA.GOV. There are a lot of public domain space images there. Some are compressed in the JPG format to save space,and some are not. Write back if you do not have the software to uncompress the images and I'll e-mail it to you. By the way, the uncompression software is for the IBM PC. Robb. James R. Linenschmidt Excessive planning is 313 Lincoln St. #72 the foe of inspiration. College Station, Texas 77840-1957 (409)696-0725 JRL8574@Venus.Tamu.Edu JRL8574@Tamvenus.Bitnet Texas A & M University AeroSpace Engineering ------------------------------ Date: Mon, 25 May 1992 23:35-EDT From: Marc.Ringuette@DAISY.LEARNING.CS.CMU.EDU To: space-tech@cs.cmu.edu Subject: UTASROC I got the following note from Australia that may be of interest. > From: phinds@pieman.compserv.utas.edu.au (Phillip Ronald Hinds) > Subject: Rocket Project(Eng. Students) > > I am writing to you, because the student Engineering Society at > our Launceston campus are starting a design project for a small > liquid fuel (probably kerosene/lox) rocket, the main aim is to exceed > mach 1. I was wondering if you knew of anyone, I/we could contact > regarding fuel chemistry and combustion chamber design. > We are currently studying the feasibilty of such a project, > and desperately need some data on the areas above. > PHILL I sent along the discussions of launcher concepts and fuels and such. Phill has joined the list. Maybe you can help him out with this: > Thanks for the info, It answers a lot of our questions and has helped us a > great deal. When we get the time to go though all of it completely, we will > definitly have a few questions for you and the group. I especially liked all > the info on the -P2 Launcher- and it sounds as though it has a great future. > We were initially going to use kero & lox, but now H2O2 looks like the best > choice, we will have to do a lot more work on that though. Would you now of > an address I could write to to get a copy of"H & H". And also do know of > any projects using N2O as an oxidiser or if it's any good. (it's easy to > get and cheap!) Thanks a GOOGLEPLEX > PHILL > > > -- > **************************************************************** > * Phillip R. Hinds Email address : > * 276 Vermont Road, phinds@pieman.compserv.utas.edu.au > * Launceston, Tasmania, > * Australia, 7250 . > **************************************************************** > ------------------------------ Date: Wed, 3 Jun 1992 13:16:02 -0700 From: "Richard Schroeppel" To: space-tech@cs.cmu.edu Subject: Should I renew my SSI membership? I recently received a reminder from SSI that I haven't renewed for 1992. I've been a supporter for >10 years, and think it's time for an assessment. (I'm posting here to avoid the mail-storm-crowd on sci.space, and since this tends to be a more thoughtful group. Also, it's a technical question: How much progress have we made, and how far do we have to go?) Much has happened since 1980: O'Neill is dead, Drexler has moved on the new things, L5 is dead, and Keith Henson has signed up with ALCOR (Cryonics) as the only likely way to ever get to space. The military has made great progress with railguns (oops, I mean mass-drivers). Our govt has spent a mint on Fred, with the promise of bending metal real soon now. Jim Scotti, Eleanor Helin, the Shoemakers, & friends have turned up a couple of dozen interesting approachable asteroids. They keep improving their equipment, so we'll see more & closer. We've seen no progress on remote manipulators, and a little bit on autonomous robots. The Russian space program shows signs of unraveling. We have pictures of Gaspra (as well as Phobos & Deimos). The Biosphere group is trying to understand what's required for an isolated colony. Bob Forward has proposed twenty-seven new ways to leave your planet. Cost to orbit hasn't changed much. Personal wealth is unchanged. There are more launch services available. Satellites have achieved a small economic niche in observation & communications, which may survive the introduction of fiber-optics. SSI has supported some good work, including asteroids searches and materials processing work with (simulated) lunar regolith. From Columbus to Plymouth Rock was 128 years. I know that people have roundly criticized "The Plan", but it would sure be nice to see some concrete progress. It looks to me like we are spinning our collective wheels: much noise & burning rubber, but not even a quarter-milestone passed. Rebuttal? Rich Schroeppel rcs@cs.arizona.edu ------------------------------ From: henry@zoo.toronto.edu Date: Wed, 3 Jun 92 17:29:42 EDT To: Richard Schroeppel Cc: space-tech@cs.cmu.edu Subject: Re: Should I renew my SSI membership? >I know that people have roundly criticized "The Plan", but it would >sure be nice to see some concrete progress. It looks to me like we >are spinning our collective wheels... If DC-Y gets funded, there is an excellent chance of getting some traction for a change. :-) I fear I don't see a lot of hope in most other directions. (A glimmering when I look at Pegasus, but it would be brighter if they were flying more often.) Henry Spencer at U of Toronto Zoology henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Wed, 3 Jun 1992 17:33-EDT From: Marc.Ringuette@DAISY.LEARNING.CS.CMU.EDU To: space-tech@cs.cmu.edu Subject: Re: Should I renew my SSI membership? I figure SSI is cost-effective because it hardly costs anything. I'll keep supporting it. If I really wanted things to happen, I'd be building some little microsats right now. It's something I have (most of) the skills to do, and doesn't cost much. I think there's a great opportunity to do useful experiments with small scale space technology. Any of us could do it if we got the energy and a co-conspirator or two. It's a great thing for college classes to try. Experiment with microsat designs in a vacuum tank. Work on better electric propulsion. Work on high temperature space power systems (thermionic is my favorite). Design a little radar for orbital rendezvous that only weighs a few ounces. Scout for asteroids with amateur telescopes. M. ------------------------------ Date: Thu, 4 Jun 92 20:11:45 -0400 From: Jon Leech To: space-tech@cs.cmu.edu Subject: Re: Should I renew my SSI membership? SSI is never going to accomplish some of the more grandoise goals they've mentioned in the past. Coming up with enough money to bootstrap space industrialization is right out. Even without Geostar's demise, it was never likely. But they do good stuff, and I renewed for a second 5 years as senior associate recently. Even on a grad student budget, $300/year isn't going to break anyone. I get a very satisfied feeling from supporting them. If nothing else, it's a concrete way to contribute to getting into space while not able to be directly involved in the technical end at present. SSI's goals are nearly identical to mine, it avoids (by and large) govt. entanglements, and not being commercial, the probability of internal politics mucking up the program is lower. It remains to be seen if SSI can keep focused after O'Neill's death, but I believe it will. I have great respect for Freeman Dyson, the acting president. Jon (leech@cs.unc.edu) __@/ ------------------------------ Date: Fri, 5 Jun 92 17:55:40 -0500 From: pgf@srl01.cacs.usl.edu (Phil G. Fraering) To: leech@cs.unc.edu, space-tech@cs.cmu.edu Subject: Re: Should I renew my SSI membership? That seals it, Lou. If they have Freeman Dyson as acting president, you (and I, for that matter) should renew... Thankfully I just got paid this week. pgf ------------------------------ From: eder@hsvaic.boeing.com (Dani Eder) Message-Id: <9206041541.AA20832@hsvaic.boeing.com> To: rcs@cs.arizona.edu Subject: Re: Should I renew my SSI membership? In a way, the purpose of SSI has been achieved. Use of non-terrestrial materials has entered mainstream aerospace thinking, which it was not when SSI got started. We lost sight of two big end-targets along the way: Solar Power Satellites solving energy problems as a reason to go to space, and Space Colonies that normal people could live in. At the time SSI was founded, the Space Shuttle was just around the corner, promising cheap transport to orbit. The 1977 NASA report "Space Settlements: A Design Study" assumed cargo delivery to orbit of $310/kg in today's dollars. As we know, the current cost is stuck at $10,000/kg, and the NLS heavy lift vehicle might reduce this to $5000/kg by the year 2000, so the required transport to orbit at a reasonable price has not materialized. In their scenario, 1 million tons over 10 years was produced to build a colony. Today, after study of space manufacturing, we know about 1-3% of the produced mass is still required to be brought from Earth (stuff too hard to make in space, plus the space manufacturing tools). So for 100,000 tons per year, we need to launch 1000-3000 tons from earth per year. At NLS prices this comes to $5-15 billion for launch costs alone, which is out of the ballpark. It comes to $5-15 million per person at the colony, which is too much for normal folk. At the projected $310/kg, we are talking $300K-900K per person, which is high but not out of the question for a colonist. There are earthly neigborhoods that expensive. The Spacewatch camera project of Tom Gehrels is very promising as far as looking for Near-Earth Asteroids, and with the recent news about asteroid cataclysms, he may get the funding for the 72 inch telescope, which will bring the discovery rate to a couple of hundred per year. SS Fred is now only months away from literally cutting metal on the Engineering Test Article (which is the ground test prototype), and about a year from start of flight hardware fabrication. While the problems of Fred are well known, the plus side is the harware being developed is generally useful for other projects. For example, life support is the same in orbit, on the Moon, or in transit to Mars, so you can use the same life support system as Fred. Fred also gives the cargo delivery market a steady customer. If the government can be convinced to open up that job to competition, it could drive an opening for cost reduction sort of the way air-mail contracts help get airlines started. Finally, the future of propulsion is looking much better than it did ten years ago. NASP has been getting real money for years, and ground launchers, lasers, etc. have been getting lots of collateral technology developed by folks like SDI. One example is the capacitors available today are much better than what the Mass Driver designs assumed. The first tether demonstration is only months away. The breakthrough in getting into space hasn't happened, but there is progress and hope. Now, to return to the question of whether SSI is a useful place to send money, I think it is no longer the lone voice crying in the wilderness. I also think that under O'Neill there was a certain rigidity of ideas, a lot of new stuff has come along that SSI has not yet accommodated in it's thinking. Personally, the jury is out for me. I'm a Senior Associate, I will complete my pledge, but I am also looking to see what direction SSI will take in the next year or two. Dani ------------------------------ Date: Mon, 8 Jun 92 07:45:50 CDT From: ssi!lfa@uunet.UU.NET (Louis F. Adornato) To: uunet!cs.cmu.edu!space-tech@uunet.UU.NET Subject: Re: Should I renew my SSI membership? I agree that any time there are humans in space, it adds to the knowledge base and brings us one step closer to being a spacefaring civilization. However... > ...While the problems of Fred are well known, the > plus side is the harware being developed is generally useful > for other projects. For example, life support is the same > in orbit, on the Moon, or in transit to Mars, so you can use > the same life support system as Fred. ..I have to disagree with this - there's a big difference between the Environmental and Life Support System (ECLSS) designed for a regularly serviced station and a long term exploration vehicle. Fred's ECLSS won't be regenerative, and there's no incentive to make it so. On the other hand, a Mars mission is going to have to go a long way towards a closed loop if they hope to get the mass of the consumables down to something reasonable (yeah, I know that NASA's position right now is that the tech- nology won't be mature enough to meet reliability criteria by launch date, but they're also going full bore on developing closed loop systems out at Ames, and I'd be willing to bet the stated position will change). The differences in missions impacts nearly every aspect of the design; the Fred's ACS avoids momenum wheels in favor of a (hydrazine-based) reaction system (this is probably due to the near-disaster that ocurred on Skylab when the bearings on one of the momenum wheels froze); Fred won't be needing much of a propulsion system; its structure won't have to be able to tolerate the orbital escape and insertion maneuvers that'll be required of a Mars vehicle; there's going to be about 4 times the available solar power - there's no need to develop onorbit nuclear power (or to develop the skills the Legal dep't is going to need to deal with the ravening mobs of enraged Rifkinites); the medical capabilities on Fred will be limited to stabilizing a patient until (s)he can be stuffed into a CERV; the list goes on and on. Probably the biggest impact Fred could have on a Mars would be in deter- mining if a crew that's operated in microgravity for as much as 18 months is going to be able to handle even the .5G of a Mars surface exploration. However, the Variable Gravity Research Facility (VGReF) has been axed. On a related note: I personally beleive (absent nearly all data...) that a Mars vehicle will need to be spun. Even after only 8 days in micrograv, with exercise, most Shuttle pilots have reported a confused kinesthetic sense (i.e., maneuvers don't feel right in the seat of the pants), and some succeptability to motion sickness. I suspect that even if the problems of reduced muscle mass and decalcification are resolved, the basic problem of coordination and balance is going to make a revolving crew compartment a necessity. Also, I've heard some complaints that NASA won't use the data that the Soviets gathered on MicroG adaptation syndrome (and that, if they did, it would make Fred _completely_ redundant...), but, given the track record that's coming to light for the Soviet medical establishment, I'm starting to suspect that this might not be a bad idea. Lou Adornato | "If I'd known I was going to live this long, Supercomputer Systems, Inc | I'd have taken better care of myself" Eau Claire, WI | The secretary (and the rest of the company) uunet!ssi!lfa or lfa@ssi.com | have disavowed any knowledge of my actions. ------------------------------ From: henry@zoo.toronto.edu Date: Mon, 8 Jun 92 16:04:54 EDT To: space-tech@cs.cmu.edu Subject: Re: Should I renew my SSI membership? >... Fred's ECLSS won't >be regenerative, and there's no incentive to make it so... Actually, I believe they plan on doing water recycling, and the incentive there is reasonably high -- when you start figuring in laundry and washing, humans living in space for long periods actually use a lot of water. Henry Spencer at U of Toronto Zoology henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Thu, 11 Jun 1992 14:34:46 -0400 (EDT) From: PLATT@WCSUB.CTSTATEU.EDU To: space-tech@cs.cmu.edu Someone posted a message to the space-tech discussion group in April that a new person was taking over the SPACE Digest as moderator. He also mentioned that they were having some hardware problems getting everything set up. I was just wondering if anyone knows if they are still having problems and when it is likely they will be fixed? I am a subscriber to the sapce digest and havent gotten anything from it since April. I have checked to see if I am still subscribed to the group and I checked the space index at UGA and I see that the last SPACE Digest is from April there also. I hope that the digest becomes active again soon I miss keeping up on the latest in space research and exploration etc. Thanks Don Platt (Platt@wcsub.ctstateu.edu) Western Ct State Univ. Astronomy Department ------------------------------ Date: Thu, 11 Jun 92 17:21:52 -0500 From: pgf@srl01.cacs.usl.edu (Phil G. Fraering) To: PLATT@wcsub.ctstateu.edu, space-tech@cs.cmu.edu Subject: About Space Digest... Apparently it's being picked up by the ISU. I would think (personally) that that wouldn't be a good idea, since the ISU has a floating campus. _This_ year it's in Japan. I've heard speculation that Toronto may end up being the ISU's permanent site after a while... Anyway, I'm off the subject now. So goodbye... pgf ------------------------------ Date: Thu, 11 Jun 92 18:31:30 EDT From: Mark.Maimone@A.GP.CS.CMU.EDU To: PLATT@WCSUB.CTSTATEU.EDU, pgf@SRL01.CACS.USL.EDU, space-tech@CS.CMU.EDU Subject: Re: About Space Digest... Hi all, The current plan is to move Space Digest to ISU Headquarters in Massachusetts. Even though the ISU is runnin a summer session in Japan, the machine that will support the digest is staying in the US. The folks maintaining the digest still have all-but-physical access to it, with other folks maintaining the hardware. So having the ISU take care of it is not a problem. The reason it's not yet back in service is that the old code doesn't work on the new hardware. We've managed to circumvent most problems, but I'm still trying to get existing code to support the email/netnews connection. This used to work via help from someone at Berkeley, but he has since left and hasn't responded to my pleas for help. If anyone knows of some source code that implements this, I'll be most appreciative to hear about it. I need something that (robustly) forwards email to sci.space (a simple esndmail front-end to a posting program would suffice), and something to forward all (non-digest) sci.space postings to a particular email address. I've already got the digest software in place, being used by two other mailing lists. Once I get this part of the connection working, everything will be back in action (including anon-ftp of future digests). Mark Maimone CMU Computer Science [helping set up Space Digest] mwm@cmu.edu ------------------------------ Date: Thu, 11 Jun 92 19:06:55 PDT From: gwh@lurnix.COM (George W Herbert) To: space-tech@cs.cmu.edu Subject: Re: About Space Digest... If ISU is going to pick it up, I'll poke real hard to make it done right. BTW, for those that don't already know, ISU may be floating campus, but they have a permanent office in Boston, and an (allegedly Internet tho I can't find it 8-) computer domain, isunet.edu ... and someone (Steve Abams) who is responsible for computer stuff. So presumably it won't go to hell in a handbasket. -george ------------------------------ Date: Thu, 11 Jun 92 15:12:25 PDT From: gwh@lurnix.COM (George W Herbert) To: space-tech@cs.cmu.edu Subject: Status Report on Big Dumb Hybrid It's been a while since I said anything about this project, so I thought I'd drop everyone a quick status report and state of the project statement... especially since I'm going to be off in Japan starting next Monday 8-) BDH has evolved and mutated some. After some deep soul searching and evaluation, three major changes have been implimented in the current working concept and one was not (switching to liquid fueled). The vehicle has gone from a fairly small cluster ( <5 units ) to a vehicle with considerably more but smaller units (1 meter diameter). This occurred for two reasons: the primary one was to better accomidate the second major change, which is to a differentially valved pressurization system for steering instead of the vanes I was touting earlier. It also will simplify (and lessen the cost of) designing and flight-rating the unit component. The third change is that Hydrogen Peroxide is now considered a "highly likely" propellant. The basic engine unit has gone from 3+- meters diameter down to about 1 meter diameter, but there are correspondingly more of them. A 9-wide hexagonal cluster (total units: 60+1 empty slot at center) of these 50m long engine units sits under a structural assembly which ties them all in place and above which the payload rests. The vehicles overall height is about 65-75m dependent on factors such as payload fairing sizing (mission dependent?). The individual engine units are released when they burn out and fall straight back off their mounts (they're only connected at the top, to the structural assembly) and away. They should lose all thrust as soon as they start to move aft: the tank top is part of the structural assembly instead of the engine unit, so as soon as it unseals the pressurization will blow. To simplify reliability, at this point the mission profile calls for using several different internal arrangements of the fuel grain within the engines; from highly starred (quick burn) through classic cylindrical (long burn). All engines ignite on the pad, with the quick-burn engines (outside) starting out at full thrust, and the long burn engines (core) running at fractional power until the quick burn engines are ready to stage off. A second set of long burn engines (the six closest to the center) wait even longer, until the rest of the long-burn engines are burnt out, before going to full power. This arrangement evens out thrust levels over the flight and makes sure that the engines are all running at launch time. The individual engine units are still using the nozzle-cooling boiler concept for pressurization, for simplicity and cost reasons. Hydrogen Peroxide is being considered to alleviate potential problems involving mixing LOX and my chosen structural steel. While my research indicates that a LOX-compatable insulation material could easily be applied to the inside of the oxidizer tank, the steel in question still has somewhat degraded mechanical properties at lower temperatures, and I'm worried that incomplete insulation coverage (or failure) might cause a structural failure in flight. H2O2 avoids any material problems, since it's a room temperature propellant. Its higher density helps offset its higher cost, but not by a whole lot. Basically, I'm trading a known per-launch cost increase for simplified engineering and less design headache. I'm sure that the launch crew will appreciate not having to worry about cryogenics, too 8-) That all having been said, my initial cost numbers of roughly $8-10 million per 10 tonne to LEO launch seem to be holding up even with the redesign... the important concepts haven't changed much, and if anything the ground expenses may drop, because instead of wrangling 3 1000+-ton (well, 450 unloaded) units into position on the pad, we're instead looking at maneuvering 60 30+-ton units (about 14 unloaded 8-) around under the structural assembly. These are about the weight of for instance a seagoing shipping container, so crane technology should make maneuvering them pretty easy. I'm shooting to have the design publishable by Dec-Feb. Further comments are of course welcome 8-) -george william herbert gwh@lurnix.com gwh@ocf.berkeley.edu gwh@soda.berkeley.edu gwh@gnu.ai.mit.edu ------------------------------ End of Space-tech Digest #122 *******************